ENH: Various command line tools.

The following command line tools are now available:

* anytocfradial: create a CF/Radial file from any radar file.
* radar_info: print out information about a radar file.
* radar_plot: create a plot for a radar file.
* check_cfradial: check that a file meets CF/Radial standards.

The main setup.py file updated to install the above scripts during install,
and PEP8 cleanup was performed on this file.
BUG: reading Sigmet file with data_type > 58.

Sigmet files which are truncated (end early) can also be read.
Closes issue #90
Merge pull request #89 from jjhelmus/master

ENH: Various command line tools.